Actress Kristen Stewart arrives for a panel discussion for the upcoming film ''The Twilight Saga Breaking Dawn Part 2'' at Comic-Con in San Diego, California July 12, 2012.

Katy Perry and Robert Pattinson have reportedly been spending more time together following the actor's recent split from Kristen Stewart, and a new report suggests the actress is unhappy.

In recent weeks Perry, 28, and Pattinson, 27, have reportedly been spotted out together on various occasions and Stewart, 23, allegedly feels betrayed by the pop star. Stewart, who is believed to have a friendship with Perry during her relationship with Pattinson, split up with her "Twilight" co-star in May.

The "Hot N Cold" singer and Pattinson reportedly attended a Bjork concert at the Hollywood Palladium in Los Angeles on Saturday. They were also allegedly spotted together at a wedding rehearsal in Santa Barbara, Calif. on May 26, and more recently the pair reportedly spent time with Perry's parents in Santa Barbara, California.

"She was only friends with Kristen for Rob," the source said adding "Now that he's single, she's open to turning their friendship into something more."

Pattinson and Stewart split in May after dating on-and-off for four years. While the actor and Perry are believed to have a platonic relationship, critics are questioning whether they could ever be more than friends.

"Katy and Robert have been spending a lot of time together recently and it's safe to say there is serious chemistry," an unnamed source told Grazia magazine.

"Katy thought the break from LA would do Rob good, and since he was no longer living with Kristen, she didn't hesitate in inviting him to join her," the source said about the pair's alleged trip to Santa Barbara adding, "But she doesn't want to ruin their friendship by rushing into anything."

Perry, who was previously married to British actor Russell Brand, was most recently dating singer John Mayer. The pair abruptly split in March, however they have reportedly been spotted together again in recent weeks.